I am trying to communicate using UART port 0 on an 8051 platform (MSC1210Y5). The routine is interrupt driven, however, I use the os_wait function in the RTX51 Tiny kernel to aid the process. I have a 16byte circular buffer which faciliates transmission/reception of data. This is my first time building an RTX51 driven code using uVision 3. My problem is that I cannot display data using an MSC1210 demo board, with the code I developed. I ran the debugger and the code seems to work fine, however when I download it to the board, it doesn't seem to work. I had previously developed a purely interrupt driven serial port routine and it worked. So I know the UART on the demo board is functional. Any hints, suggestions... Thanks